In 1992-94, an epidemiologic investigation of upper extremity musculoskeletal and peripheral nerve disorder ("upper extremity disorder") was carried out in an automotive stamping plant and an automobile engine manufacturing plant. A cross-sectional study of 1,198 workers in six department groups obtained both morbidity and exposure data, which also served as the baseline data for a one year follow-up survey. Upper extremity disorders, defined both on the basis of symptoms and physical examinations, were found to be strongly associated cross-sectionally with an index of ergonomic exposure that included work pace, manual force, non- neutral postures and segmental vibration. In the one-year follow up study, both the incidence of new disorders and the persistence of existing disorders from baseline were also associated with high ergonomic exposure to the upper extremity. All association persisted after controlling for numerous potential confounding variables. The proposed study will return to the same two facilities and collect additional morbidity and exposure data at about six years after the baseline survey. The overall objective is to seek to confirm and expand upon the previous associations of upper extremity disorders with occupational ergonomic stressors. All eligible works from the baseline study will be sought for interviews and examinations at the workplace or at home, in the case of retired workers. Morbidity information will be obtained from standardized questionnaire, screening physical examination, grip and pain strength, vibrometry, and pressure pain threshold testing. The interviews will also inquire as to work history, medical and injury history, smoking, recreational activities, and other potential confounding factors since the baseline interview. Exposure data on key substantive areas of investigation are: 1) changes in previously assessed exposures in the study jobs will be determined, and these will be supplemented with observations of physical exposures in non-cyclical work and with new information on work organization characteristics of all study jobs; 2) the cumulative incidence of new upper extremity musculoskeletal disorders will be estimated as a function or ergonomic exposures assessed at baseline (and at the one year follow-up, for some workers) and in this survey; and 3) the persistence of previously identified upper extremity musculoskeletal disorders will be estimated, again as a function of prior and current ergonomic exposures. In addition to these substantive question, several methodological issues will be explored, including the magnitude, if any, of the "healthy worker" selection effect operating in this population; the validity of the psychophysical exposure ratings utilized in the previous study, the short and long-term reproducibility of workers' recall of occupational exposures, and the reproducibility and sensitivity of pressure pain threshold muscle testing as a recently proposed field screening instrument.